What is ICD-10 code I70.261?

I70.261 is the ICD-10-CM diagnosis code for Atherosclerosis of native arteries of extremities with gangrene, right leg. Hardening of arteries in the right leg that has progressed to tissue death (gangrene) due to severe lack of blood supply. I70.261 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. I70.261 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. I70.261 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. I70.261 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for I70.261?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For I70.261, V28 maps to Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene at RAF 1.118 while V24 mapped to Atherosclerosis of the Extremities with Ulceration or Gangrene at RAF 1.488. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting I70.261?

Gangrene is a serious complication requiring documentation of extent and whether wet or dry gangrene Verify right leg is specifically documented; gangrene indicates advanced peripheral arterial disease Because I70.261 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

I70.261: Atherosclerosis of native arteries of extremities with gangrene, right leg — ICD-10

ICD-10-CM Code View

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Code lookupI70.261Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the circulatory system (I00-I99) / Diseases of arteries, arterioles and capillaries (I70-I79)

I70.261

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Atherosclerosis of native arteries of extremities with gangrene, right leg

Hardening of arteries in the right leg that has progressed to tissue death (gangrene) due to severe lack of blood supply.

Buddy Insight

CMS-HCC V28

Mapped

HCC 263

Atherosclerosis of Arteries o...

RAF 1.118

CMS-HCC V24

Mapped

HCC 106

Atherosclerosis of the Extrem...

RAF 1.488

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 106

Atherosclerosis of the Extrem...

RAF 0.0

RXHCC

Not risk-adjusted for this model/period.

RAF 0

Code Trumping

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Code Book Path

Official

I70.2Atherosclerosis of native arteries of the extremities

I70.26Atherosclerosis of native arteries of extremities with gangrene

I70.261Atherosclerosis of native arteries of extremities with gangrene, right leg

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for I70.261 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for I70.261 in this effective period.

Related Child Codes

Official

I70.262Atherosclerosis of native arteries of extremities with gangrene, left leg

I70.263Atherosclerosis of native arteries of extremities with gangrene, bilateral legs

I70.268Atherosclerosis of native arteries of extremities with gangrene, other extremity

I70.269Atherosclerosis of native arteries of extremities with gangrene, unspecified extremity

Includes

Official

any condition classifiable to I70.21-, I70.22-, I70.23-, I70.24-, and I70.25-
chronic limb-threatening ischemia of native arteries of extremities with gangrene
critical limb ischemia of native arteries of extremities with gangrene

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for I70.261 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for I70.261 in this effective period.

Use Additional

Official

code to identify the severity of any ulcer (L97.-, L98.49-), if applicable

Code Also

Official

ICD-10-CM does not list Code Also instructions for I70.261 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider

Specification of the affected vessel type (native arteries)

Laterality clearly documented (right leg)

Explicit documentation of gangrene — type (dry or wet), extent, and anatomic location

MEAT Support

HCC Buddy guidance

Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider

Specification of the affected vessel type (native arteries)

Laterality clearly documented (right leg)

Explicit documentation of gangrene — type (dry or wet), extent, and anatomic location

Audit Caution

HCC Buddy guidance

Coding bypass graft atherosclerosis codes (I70.3xx-I70.7xx) when the disease is in native arteries — verify whether the patient has a history of bypass graft surgery before selecting the code category

Undercoding gangrene as ulceration — when tissue necrosis/gangrene is documented, it should not be downgraded to ulceration even if ulcers are also present

Using the nonspecific gangrene code I96 instead of the combination code that captures both atherosclerosis and gangrene

Failing to assign additional codes for any associated rest pain (I70.22x) or ulceration codes if both conditions are present in addition to gangrene on the same or different extremities

Common Mistakes

HCC Buddy guidance

I70.3xx (bypass graft series) — Use I70.3xx when atherosclerosis involves a bypass graft rather than native arteries; the graft type must be specified when known

I70.231-I70.25 (native arteries with ulceration) — Gangrene codes represent more severe tissue damage than ulceration alone; do not downcode to ulceration when gangrene is documented

I70.221-I70.229 (native arteries with rest pain) — Rest pain codes are insufficient when gangrene has developed; gangrene codes already encompass the lower severity stages

I96 (Gangrene, not elsewhere classified) — Do not use this nonspecific gangrene code when the etiology is atherosclerotic peripheral arterial disease

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is I70.261 an HCC code?

Yes. I70.261 maps to Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene under the CMS-HCC V28 risk adjustment model (and Atherosclerosis of the Extremities with Ulceration or Gangrene under V24).

HCC Category Mapping

V28HCC 263, Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene

1.118

V24HCC 106, Atherosclerosis of the Extremities with Ulceration or Gangrene

1.488

ESRDHCC 106, Atherosclerosis of the Extremities with Ulceration or Gangrene

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work I70.261 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for I70.261

For I70.261to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed I70.261 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

I70.261 is the ICD-10-CM diagnosis code for atherosclerosis of native arteries of extremities with gangrene, right leg. Hardening of arteries in the right leg that has progressed to tissue death (gangrene) due to severe lack of blood supply. I70.261 sits in the ICD-10-CM chapter for diseases of the circulatory system (i00-i99), within the section covering diseases of arteries, arterioles and capillaries (i70-i79).

Under the CMS-HCC V28 risk adjustment model, I70.261 maps to Atherosclerosis of Arteries of the Extremities with Ulceration or Gangrene (HCC 263) with a community, non-dual, aged base RAF weight of 1.118. Under the older CMS-HCC V24 model, I70.261 maps to Atherosclerosis of the Extremities with Ulceration or Gangrene (HCC 106) with a community, non-dual, aged base RAF weight of 1.488. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Gangrene is a serious complication requiring documentation of extent and whether wet or dry gangrene. Because I70.261 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for I70.261 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Gangrene is a serious complication requiring documentation of extent and whether wet or dry gangrene
•Verify right leg is specifically documented; gangrene indicates advanced peripheral arterial disease

Clinical Significance

Atherosclerosis of native arteries with gangrene represents the most severe stage of peripheral arterial disease (Fontaine Stage IV/Rutherford Category 5-6), indicating tissue death due to critical limb ischemia. This diagnosis carries extremely high morbidity with significant risk of amputation, sepsis, and mortality, requiring urgent vascular intervention. Accurate capture is essential for risk adjustment as it reflects the highest severity of peripheral vascular disease and drives substantial resource utilization.

Documentation Requirements

✓Clinical diagnosis of peripheral atherosclerosis explicitly documented by the provider
✓Specification of the affected vessel type (native arteries)
✓Laterality clearly documented (right leg)
✓Explicit documentation of gangrene — type (dry or wet), extent, and anatomic location
✓Confirmation that gangrene is due to atherosclerotic peripheral arterial disease
✓Vascular assessment findings documenting the severity of arterial insufficiency
✓Current treatment plan including surgical consultation, debridement, revascularization, or amputation considerations
✓Assessment for sepsis or systemic infection if wet gangrene is present

Commonly Confused Codes

•I70.3xx (bypass graft series): Use I70.3xx when atherosclerosis involves a bypass graft rather than native arteries; the graft type must be specified when known
•I70.231-I70.25 (native arteries with ulceration): Gangrene codes represent more severe tissue damage than ulceration alone; do not downcode to ulceration when gangrene is documented
•I70.221-I70.229 (native arteries with rest pain): Rest pain codes are insufficient when gangrene has developed; gangrene codes already encompass the lower severity stages
•I96 (Gangrene, not elsewhere classified): Do not use this nonspecific gangrene code when the etiology is atherosclerotic peripheral arterial disease
•R02 (Gangrene, not elsewhere classified: legacy): This code is no longer valid; use the combination code that identifies both the atherosclerosis and gangrene
•E11.52 (Type 2 diabetes with diabetic peripheral angiopathy with gangrene): Use this code when gangrene is attributed to diabetic peripheral angiopathy rather than primary atherosclerosis